Pressure sampling device



Jan. 28, 1964 w, M. HAUNSCHILD 3,119,272

PRESSURE SAMPLING DEVICE Filed Dec. 26, 1961 INVENTOR WILLARD M. HAUNSCHILD TTO RN EYS United States Patent i '1 ill 3,11%,272 PRESSURE SAMPLING DEVICE Willard M. ll'aunschiid, Walnut Creek, Calih, assignor to California Research t'lorparation, San Francisco, Calm, a corporation of Delaware Filed Dec. 26, 196i, S-er. No, 162,949 4 (Claims. (Cl. 73-4254) This invention relates to sampling devices, and more particularly to devices for extracting fluid samples from systems containing larger bodies of said fluids and for injecting fluid samples into other systems.

In the operation of many process systems containing stationary or moving beds of fluid it is necessary to extract a fluid sample from the system for examination or analysis. It also is frequently necessary to inject into various systems small amounts of fluid. Frequently the systems involved are under pressure, and, while extraction of a sample may be made under pressure, it is necessary to remove the pressure from the sample in order that the sample may be transferred to a different system for examination or analysis. For example, in catalytic reforming research it frequently is necessary to extract a reaction mix sample from a process system and subject the sample to chromatographic analysis. In order to do so, it is necessary to release the pressure on the sample so that it separates into liquid and gas phases, chromatographically analyze each phase, and calculate the original composition from the analysis and amounts of the liquid and gaseous phases. Such a laborious method inherently involves inaccuracies and analytical inefliciencies.

In view of the foregoing, it is an object of the present invention to provide an improved sampling device capable of abstracting from a fluid body under pressure a sample of said fluid under pressure, and further capable of injecting into a pressure system a sample of fluid under pressure.

In accordance with the present invention there is provided sampling apparatus for extracting from a fluid body un er pressure a fluid sample and for expelling said fluid sample from said apparatus which comprises a chambercontaining body member constructed to withstand a pressure in said chamber of at least 500 p.s.i.g., fluid inlet means communicating through said body member to said chamber, means within said body member slidable across the opening of said inlet means to said chamber for sealin; fluid in said chamber under pressure by sealing off said inlet means from said chamber, separate plunger means communicating with said chamber for drawing fluid into said chamber and for expelling fluid from said chamber when said inlet means are open.

In a more specific embodiment of the present invention, there is provided a syringe comprising a tubular barrel having a longitudinal bore, two opposing plungers located in said bore, fluid inlet means located at right angles to said barrel in a wall thereof and communicating with said bore, said plungers and said inlet means being so located that inward travel of the first of said plungers in said bore closes off said inlet means and outward travel of said first plunger opens said inlet means, whereby with said inlet means open fluid may be drawn into said bore by outward travel of the second of said plungers and said fluid may be sealed in said bore by inward travel of said first plunger.

By pro er design of the apparatus of the present invention for operation at any desired pressure, it has been found that with the apparatus fluid samples at the original system pressure may be quickly and efficiently obtained from fluid bodies under pressure, and said samples may be injected into other systems as desired, for example into chromatographic analysis equipment.

The novel features of the invention are set forth with particularity in the appended claims. The invention will best be understood, however, both as to organization and operation, and additional objects and advantages thereof will be apparent from the following description of specific embodiments of the invention when read in connection with the accompanying drawing. In the accompanying drawing:

FIG. 1 is an elevation View, in partial section, of a syringe constructed in accordance with the present invention, indicating two opposing plungers in the bore of the syringe barrel; the plungers are shown in a separated position in which their opposing ends and a portion of the barrel bore form a chamber containing a fluid drawn into the chamber through the syringe inlet means by outward movement of the upper plunger in the bore;

FIG. 2 is a transverse section of the apparatus shown in FIG. 1, taken along the lines 22;

FIG. 3 is a sectional elevation view of the apparatus shown in FIG. 1, taken along approximately the longitudinal centerline of the apparatus at right angles to the view shown in FIG. 1.

Referring now to FIG. 1, by the general construction of the specific embodiment of the invention shown there, it will be seen that the syringe in that embodiment has two plungers instead of one as in an ordinary syringe. Members 2 are secured to cross members 3, 4 and 5 as shown, to form a rigid framework or yoke. Grooves 6 are provided in syringe barrel ltl so that members 2 may act as a track on which syringe barrel 10 moves between cross members 4 and 5. Finger pulls 11 are provided, as in a conventional syringe, for pulling syringe barrel 10 upward between cross members 4 and 5. Inlet means comprising needle 12, packing gland nut 13 and a sealing O-ring 14 are provided as shown. The longitudinal hole through needle 12 communicates with syringe bore 24 through aperture 15. Upper plunger 19, actuated through plunger handle 29 and thumb operable button 21, is slidably positioned in bore 24 as shown. Upper plunger 19 is provided with an adjustable stop nut 22 to limit the upward travel of plunger 19 in bore 24, and is provided with a sealing Q-ring 23 mounted in a groove on plunger 19 to prevent fluid entering through needle 12 from passing upwardly in bore 24 alongside plunger 19.

Lower plunger 36, having two sealing O-rings 31 and 32 mounted in grooves thereon, is secured to lower cross member 5 by being threaded into lower cross member 5 to a desired location and locked at said location with lock nut 33.

Still referring to FIG. 1, in the operation of the device there shown, when barrel 10 is in the position shown with respect to cross member 4, aperture 15 is not obstructed by plunger 39 and O-rings 31 and 32. Accordingly, with barrel iii in this position and with sharp end of needle 12 inserted into a fluid body from which a sample is to be withdrawn, upon raising of plunger 159 with respect to barrel ill a fluid sample is drawn into bore 24- of barrel 1% through needle 12 and aperture 15. When a sufficient quantity of the fluid sample is in bore 24, it is trapped there between O-ring 23 on upper plunger 19 and O-ring 32 on lower plunger 39 by sliding barrel ill downward along tracks 2 toward cross member 5. This sliding action moves terminal Q-ring 32 and lower plunger across filling port or aperture 15 thereby trapping the sample in bore 24. Second O-ring 31 on plunger 30 prevents leakage of fluid in needle 12 into bore 24 alongside plunger 36 Still referring to FIG. 1, the trapped sample in bore 24 is discharged by the same method used in an ordinary syringe. Plunger 19 is pushed downwardly in barrel 10 by thumb pressure on thumb operable button 21 and by upward finger pressure on finger pulls 11 mounted on barrel 10. This combined finger and thumb action operates to pull barrel upwardly along tracks 2 to cross memher 4, thereby removing aperture from its sealed position between O-rings 31 and 32 on plunger 30 and drives plunger 19 downwardly into bore 24 to expel from the syringe through needle 12 the fluid sample previously trapped in bore 24.

Referring now to FIG. 2, there shown is a sectional view of the apparatus shown in FIG. 1, taken along the line 2-2 in FIG. 1, showing barrel 10 located on frame members or tracks 2 in grooves 6, and showing cross member 5, plunger 30 and O-ring 31.

Referring now to FIG. 3, there shown is a longitudinal sectional view, taken along about the longitudinal centerline of the device shown in FIG. 1 and taken at right angles to the view shown in FIG. 1. FIG. 3 illustrates the method of securing track members to the cross members 3, 4 and 5. It further shows plunger 19 located in bore 24 and barrel 10, including the method of detachably connecting plunger 19 to extension or handle 20 and thumb operable button 21. Also shown is adjustable stop nut 22 for limiting the upward travel of plunger 19. The exemplary method of adjustably locating plunger in cross member 5 with a screwed connection and a lock nut 33 is shown.

The selection of the various materials of construction of the above described embodiment is within the skill of the art. The precise materials of construction selected for particular applications may, of course, depend upon system pressure, fluid corrosivity, and other factors. Generally speaking, the syringe plungers and inlet needle may be of stainless steel, the syringe barrel may be brass, and the various O-rings may be rubber or fluoroelastomers.

A syringe constructed in accordance with the abovedescribed embodiment has provided extensive and satisfactory use under pressures of 500 p.s.i.g and has provided satisfactory, although less extensive, use at pressures of 1000 p.s.i.g. I.e., the syringe has been used to obtain under system pressure fluid samples from a body of fluid in a pressured system. The maximum operating pressur for which the syringe may be constructed can be as high as several thousand pounds, although at very high pressures it is preferable that the filling port or aperture between the filling needle and the bore of the syringe barrel be as small as possible, in order to prevent abrasion of the O-ring on the lower plunger as it travels across the filling port. It will be apparent to those skilled in the rat that the fluid body under pressure from which a sample is to be taken may be a liquid, gas or vapor, and that in order to take the sample it is only necessary that a very small hole in the Wall of the pressure system be sealed with a rubber or similar seal, puncturable by the sampling needle of the pressure syringe and self-sealing upon removal of the sampling needle.

The size of the sample to be obtained under pressure will vary slightly with system pressure because of deformity of the O-rings of the syringe. Calibration of the syringe accordingly should be made at the pressure at which it will be used. By use of suitably located stop nuts, which limit the upward travel of the upper plunger, any size sample may be obtained up to the maximum capacity of the plunger barrel.

The film of non-volatile material which remains in the barrel and needle of the syringe described above after expulsion of the contents thereof may be a source of error. The needle error can be largely eliminated by proper technique of syringe use so that the film in the needle is the same before and after the syringe contents are expelled. The O-rings wipe clean the bore of the syringe barrel, but after expulison of the syringe contents a film of the fluid sample remains on the ends of the plungers. The resulting error can be made small by careful design and machining and by use of as large a sample as possible.

As previously discussed, the apparatus of the present invention has utility in Withdrawing and injecting samples of various fluids, including gases and liquids, particularly while maintaining said fluids at pressures under which the bodies of fluid from whichthey were taken existed.

Exemplary uses of the apparatus of the present invention for pressure sampling include:

(1) Injection of a sample of a liquid phase into a chromatograph;

(2) Injection of H 5 or mercaptan into a catalyst treating system to presulfidc a catalyst;

(3) Injection of trace quantities of reagents into a catalyst manufacturing operation to control catalyst composition;

(4) Injection of radioactive tracers into process lines;

and

(5) Injection of hydrocarbon feeds into laboratory microreactors.

It will be understood that many modifications in the apparatus of the present invention can be made without departing from the basic features of the invention or from the spirit and scope thereof, including reversal of location of components thereof such as reversal of location of the inlet and the lower plunger of the embodiment described above. All such modifications are intended to be included Within the scope of the appended claims.

I claim:

1. Sampling apparatus for extracting from a fluid body under pressure a fluid sample under pressure and for expelling said fluid sample from said apparatus, which comprises a chamber-containing body member constructed to withstand a pressure in said chamber of at least 500 p.s.i.g., fluid inlet means communicating through said body member to said chamber, means within said body member slidable across the opening of said fluid inlet means to said chamber for sealing fluid in said chamber under pressure by sealing off said fluid inlet means from said chamber, and separate plunger means communicating with said chamber for drawing fluid into said chamber and for expelling fluid from said chamber through said fluid inlet means when said fluid inlet means are open.

2. A syringe comprising a tubular barrel having a longitudinal bore, two opposing plungers located in said bore, fluid inlet means located in a wall of said barrel and communicating with said bore, said plungers and said inlet means being so located that inward travel of the first of said plungers in said bore closes off said inlet means and outward travel of said first plunger opens said inlet means, whereby with said inlet means open fluid may be drawn into said bore by outward travel of the second of said plungers and said fluid may be sealed in said bore by inward travel of said first lunger, and means for operating said first plunger.

3. Pressure sampling apparatus comprising an elongated barrel member having a bore therethrough on the longitudinal center axis thereof, two opposing plungers slidably located in said bore, in such sealing relationship to said bore that liquid in the space between the opposing ends of said plungers is prevented from flowing into the space between said plungers and said bore, inlet means comprising a tube located in a side of said barrel member and communicating with the bore thereof, said inlet means being open to said bore when the first of said plungers is in a retracted position and closed to said bore by the inward travel of said first plunger into said bore, whereby retraction of the second of said plungers when said first plunger is in a retracted position will permit a fluid to be drawn through said inlet means into said bore, whereby said fluid will be trapped in said bore between the opposed ends of said plungers by the inward travel of said first plunger, and whereby the outward travel of said first plunger will uncover said inlet means and the inward travel of said second plunger will expel said fluid from said bore through said inlet means, and means for operating said first plunger.

4. A high pressure hypodermic syringe comprising two parallel metal bar yoke members maintained in spaced relationship by attachment of each end thereof to a separate cross member, a syringe barrel located between said yoke members with the longitudinal axis thereof parallel to said yoke members, two opposing plungers slidably located in the bore of said syringe barrel, a first of said plungers being secured to one of said cross members, the second of said plungers having an elongated longitudinal extension thereof passing through the other of said cross members and terminating in a thumb-operable push button secured at right angles thereto, inlet means located in a side of said barrel and communicating with said bore at right angles thereto, said first plunger located with respect to said inlet means to cover said inlet means on inward travel of said first plunger into said bore and to uncover said inlet means on outward travel of said plunger from said bore, finger-pull means attached to the sides of said barrel for sliding said bore along said yoke with respect to said first plunger to uncover said inlet means, whereby outward travel of said first plunger in said bore uncovers said inlet means and outward travel of said second plunger in said bore draws fluid through said inlet means and into the chamber formed by said bore and the opposing faces of said plungers, and whereby inward travel of said first plunger traps said fiuid in said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 103,027 Dieula-foy May 17, 1870 OTHER REFERENCES Article by Porter et al., Gas Chromatographic Determination of Fuel Dilution in Lubricating Oils, Analytical Chemistry, vol. 31, No. 5, May 1959, page 867. 

1. SAMPLING APPARATUS FOR EXTRACTING FROM A FLUID BODY UNDER PRESSURE A FLUID SAMPLE UNDER PRESSURE AND FOR EXPELLING SAID FLUID SAMPLE FROM SAID APPARATUS, WHICH COMPRISES A CHAMBER-CONTAINING BODY MEMBER CONSTRUCTED TO WITHSTAND A PRESSURE IN SAID CHAMBER OF AT LEAST 500 P.S.I.G., FLUID INLET MEANS COMMUNICATING THROUGH SAID BODY MEMBER TO SAID CHAMBER, MEANS WITHIN SAID BODY MEMBER SLIDABLE ACROSS THE OPENING OF SAID FLUID INLET MEANS TO SAID CHAMBER FOR SEALING FLUID IN SAID CHAMBER UNDER PRESSURE BY SEALING OFF SAID FLUID INLET MEANS FROM SAID CHAMBER, AND SEPARATE PLUNGER MEANS COMMUNICATING WITH SAID CHAMBER FOR DRAWING FLUID INTO SAID CHAMBER AND FOR EXPELLING FLUID FROM SAID CHAMBER THROUGH SAID FLUID INLET MEANS WHEN SAID FLUID INLET MEANS ARE OPEN. 